It affects every region of the globe – credible deterrence limits the impact

The large-scale Russian invasion of Ukraine now underway could quite plausibly precipitate a wider conflict in Europe. The United States is focused primarily on raising the costs to Russia with punishing sanctions and reassuring North Atlantic Treaty Organization (NATO) allies neighboring Russia of its commitment to collective defense. Less attention has been given to containing the war to Ukraine and preventing its escalation into a broader European conflict.

The stakes are enormous. The ripple effects of a wider conflict in Europe would spread across the globe, stressing the geopolitical, economic, and institutional foundations of the international order the United States has fashioned and underwritten since the end of the Second World War. It would test the resilience of the U.S. global system of alliances, the international financial system, global energy markets, arms control regimes, and global institutions in the face of ever more violent great power competition. No region of the world would be spared, although developments on the Eurasian supercontinent, the other locus of world power and economic might outside North America, would bear the gravest consequences for U.S. interests.

The Contingency

The Russian military intervention in Ukraine could easily escalate into a larger conflict stretching from the Baltic to the Black Sea and further west into Europe. Although Russia, wielding massive military superiority, might overrun Ukrainian forces in a matter of weeks, stabilizing and pacifying the country will likely prove to be a grueling and costly affair. A significant Ukrainian resistance movement is almost certain to emerge. With sustained Western support, it could prolong the warfare for months, if not years. The first wave of sanctions that Washington has levied on Moscow could be followed by others in a continuing effort to raise the cost to Moscow and force it to yield. A negotiated end to the conflict will not come easily, since Washington has framed it in Manichean terms as a world historical struggle between the democratic West and the aggressive, malevolent, and autocratic Russia. Anything short of “victory” will be decried as surrender or appeasement in the West, while Russia will not capitulate on a matter it considers vital to its security and prosperity.

The stage is thus set for an escalating cycle of violence, with Moscow seeking to stamp out a Ukrainian insurgency and retaliate against Western efforts to stop Russia’s advance. If the conflict wears on, Moscow could be increasingly tempted to expand its military operations further into Europe to achieve its goals.

As a first option, Russia could intensify pressure on states neighboring Ukraine (e.g., Hungary, Poland, Romania, and Slovakia) that could provide safe havens for insurgents or the inevitable government-in-exile. It will doubtless reinforce its military presence in Kaliningrad and elsewhere in the Baltics and patrol the Baltic Sea more aggressively. It could deploy hybrid-war tactics—cyberattacks, disinformation campaigns, and economic sabotage—to destabilize countries providing safe havens. If those actions did not sufficiently degrade the resistance, Moscow could even launch direct attacks on insurgents and their supporters outside Ukraine, as well as attempt to assassinate leading figures in the government-in-exile, akin to the attacks it has made on Chechen rebels and Federal Security Service (FSB) defectors in Europe in recent years. Such steps could, at a minimum, draw frontline NATO states directly into the military conflict with Russia, obligating the United States and other allies to come to their defense.

To build up further pressure, Moscow could also “weaponize” the inevitable refugee flows into neighboring states. Refugees, who would likely number in the millions, would move first into unoccupied Ukrainian territory but eventually into adjacent European states, which have shown little tolerance for outsiders. Moscow could use harsh military and police tactics that would increase the number of refugees and seek to guide them into countries where they would create the greatest socioeconomic stress, such as Moldova. In addition, Moscow could increase the tension by pushing Belarusian President Aleksandr Lukashenko to again seek to push thousands of Middle Eastern migrants across the borders into Poland and Lithuania. That could lead to border clashes, as it almost did on occasion last fall, with Russia supporting its ally, Belarus, and NATO states coming to the defense of allies under attack.

A second option Moscow could pursue is opening up a second front in the Balkans. In recent years, Russia has taken a number of destabilizing actions in the region, seeking to weaken Montenegro after its accession to NATO, exacerbate tensions between Serbs and Bosniaks in Bosnia-Herzegovina, and undermine relations between Serbia and Kosovo. As it fought in Ukraine, Russia could encourage Republika Srpska leader Milorad Dodik to press for separation from Bosnia, threatening to reignite the bitter wars of the 1990s in the former Yugoslavia. A Balkans war would complicate the security calculus of all countries in the region, as well as that of Germany and France, which have significant interests there. To quell the fighting, NATO countries could decide to use military force against Bosnian Serb forces enjoying Russian support.

A third, riskier, option would be to directly attack the United States, the country that Moscow believes is orchestrating a larger anti-Russia campaign. In response to Western sanctions designed to crater Russia’s financial system and undermine critical industries, Moscow could launch major cyberattacks against U.S. critical infrastructure. If a cyberattack were to take down a major financial institution or corrupt its records, the ensuing havoc in U.S. markets could prompt overwhelming public and congressional pressure for a forceful response.

The U.S. and NATO response to Russian actions will impact Moscow’s decisions on the conduct of the conflict. Both a weak response and an excessively harsh one could lead to escalation. In the first case, Moscow could be tempted to press militarily even further into Europe to enlarge its sphere of influence. Vladimir Putin has demanded that NATO withdraw its forces back to the lines they held in 1997, when the NATO-Russia Founding Act was signed and the first wave of post−Cold War expansion remained in the future. His remarks announcing the start of hostilities against Ukraine hinted at a broader effort to restore Russia’s control over all of the former Soviet Union. That could include military action against the Baltic states, especially Lithuania, through which Moscow could try to carve out a land corridor to Kaliningrad, a Russian exclave on the Baltic Sea. NATO would have little choice but to provide military aid to those states if it did not want to forfeit its role as the central pillar of European security.

Crippling sanctions, meanwhile, could provoke Putin to lash out with greater violence. If Putin felt cornered, he could escalate the conflict either horizontally to other countries or vertically to the nuclear level in a desperate effort to save himself, his regime, and, in his mind, Russia itself. And he could find considerable public support for such a reaction. Already, some Russians believe that U.S. and EU sanctions are aimed not simply at the leaders behind the war but, by cratering the economy, at all Russians.